Feasibility of development of a sensitive and convenient kit to detect and follow certain hematologic malignancies, e.g. leukemias, multiple myelomas, lymphomas, sarcomas, and related conditions is proposed. Sera from mice and humans with these malignancies contain a heterogenous group of double-stranded, primarily repetitive DNA sequences which inhibit the activity of certain DNA polymerases. These DNAs are found in much smaller amounts (if at all) in healthy individuals. The sequences are known. The proposed test is estimated to be several orders of magnitude more sensitive than current tests, and thus may aid in detection of these malignancies in patients who present with a suspected diagnosis based on laboratory values or symptoms, for whom detection and diagnosis are elusive because there are insufficient malignant cells present for detection and diagnosis using current procedures. DNA from sera will be compared between patients and healthy individuals. Levels of known DNAs from the above malignancies will be assayed in additional patients with these, other malignancies, and with non-malignant conditions to determine sensitivity and specificity of this test. In Phase II, an automated kit for commercial use will be developed. PROPOSED COMMERCIAL APPLICATIONS: Assay of unique DNA-L sequences will enable laboratories to provide detection and status information on the occurrence, progression and regression following treatment of selected malignancies using a small amount of serum. Use of such a sensitive and economically feasible assay will increase acceptability of testing, allowing earlier detection and closer monitoring of disease status and effectiveness of therapy. Early detection could enable less expensive therapy and, potentially, more cures because of a smaller tumor load to eradicate, increasing the well being of patients and decreasing the cost of medical care.